Research has consistently shown that risk for substance abuse starts early, much earlier than when children actually initiate substance use. It is important to further study the pathways that lead to substance abuse to better refine current prevention and intervention strategies. Research has linked aggression to later substance use, however, aggression is not a unidimensional construct. Aggressive acts can be divided into two forms, proactive and reactive. Proactive aggression is goal-oriented and calculated, and is motivated by external reward, and reactive aggression is impulsive and occurs in response to behavior that is perceived as threatening or intentional. Proactive and reactive aggression differentially relate to outcomes such as delinquency and internalizing problems. However, little research has examined how proactive and reactive aggression relate to substance use. Thus, it is proposed to examine a conceptual model of risk that links proactive and reactive aggression to substance use. The specific aims of this proposal are: 1) examine whether proactive aggression, reactive aggression, or both are related to the development of substance use, 2) identify potential moderators (parenting and effortful control) of the relationship between proactive and reactive aggression and risk factors of substance use (delinquency and negative emotions), and 3) examine potential mediators (peers) of the relation between these two forms of aggression and substance use.